<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        /* font-weight */
        /* 
         */
        p {
            /* 取值范围100-900 */
            /* 
                1-400  细字体
                500-900  
            */
            font-weight: normal;
        }
    </style>
</head>

<body>
    <p>设置字体加粗</p>
    <p style="font-weight: 900;">设置字体加粗</p>
</body>

</html>